This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. ABSTRACT We recently completed a double-blind placebo-controlled human laboratory study demonstrating that treatment with a low dose of the acetylcholinesterase (AChE) inhibitor rivastigmine reduced methamphetamine (MA)-induced craving (see Preliminary Studies, Fig. 2). This finding is consistent with the preclinical report indicating that the AChE inhibitor donepezil reduced MA-seeking behavior in rats following exposure to a non-contingent dose of MA (Hiranita et al. 2006). To extend our clinical findings, we propose a 3-year human laboratory study to evaluate effects of higher doses of rivastigmine on MA-induced craving and on self-administration of MA. Our recently completed work indicates that 3mg rivastigmine attenuated MA-induced craving in the laboratory. Given that higher dosages of this produce greater inhibition of nicotinic acetylcholine (ACh) receptors (in the treatment of Alzheimers disease), it is reasonable to predict that 6mg and 12mg will have more pronounced effects on craving and other measures of reinforcement. This human laboratory study is a critical next step in the evaluation of rivastigmine as a potential treatment for MA dependence. We propose to include only participants exhibiting MA-induced craving by screening potential participants prior to admission (criterion based upon Preliminary Studies, Fig. 5). Selection of participants demonstrating MA-induced craving will facilitate assessment of effects of rivastigmine on craving.